Conditional Format Based on Cell Value - Getting Method Range of object Global failed erro

I am trying to apply conditional formatting to a report. Shading will occur for regions and certain cells pertaining to that region that need to be reviewed. Each region and corresponding cells to review are shaded the same color - a different color for each region.

The code I have below shows a couple of the regions but I am getting a Run-time error - Method Range of object Global failed. I have tried changing the line of code several ways but I haven't had any luck. And as you will see below, there are many lines written exactly the same so while it is stopping near the top, this error really occurs throughout. I realize that I can record this but I am trying to shorten the code and hopefully it would run more efficiently.

I would appreciate any guidance or ways this code could be corrected and/or better written. Also, since I still learning, I would appreciate bits of explanation so I can make notes in the code for future use/guidance.

    Sub CondFormat()
'   Apply conditional formatting by Region for items that need review

    Dim count, b As Long
    count = ActiveSheet.Cells(Rows.count, "A").End(xlUp).Row   'Column A has no gap in data
    b = 2  'data starts at row 2
    Do While b <= count

'   Region A
    If Cells(b, 1).Value = "Region A" Then
        Range(Cells(b, 1)).Interior.Color = RGB(180, 198, 231)      'Region  This line is where Debug stops
        Range(Cells(b, 7).Cells(b, 7)).Interior.Color = RGB(180, 198, 231)      
        Range(Cells(b, 20).Cells(b, 20)).Interior.Color = RGB(180, 198, 231)    
        Range(Cells(b, 19).Cells(b, 19)).Interior.Color = RGB(180, 198, 231)   
    End If
    
    If Cells(b, 1).Value = "Region A" And Cells(b, 25).Value = "Invalid" Then
        Range(Cells(b, 25).Cells(b, 29)).Interior.Color = RGB(180, 198, 231)   
    End If
       
    If Cells(b, 1).Value = "Region A" And Cells(b, 25).Value = "Invalid " Then   'space after invalid
        Range(Cells(b, 25).Cells(b, 29)).Interior.Color = RGB(180, 198, 231)    
    End If
           
    If Cells(b, 1).Value = "Region A" And Cells(b, 22).Value = 0 Then
        Range(Cells(b, 22).Cells(b, 22)).Interior.Color = RGB(180, 198, 231)    
    End If
        
    If Cells(b, 1).Value = "Region A" And Cells(b, 5).Value = 1 _
        And Cells(b, 31).Value = "No info" Then
        Range(Cells(b, 5).Cells(b, 5)).Interior.Color = RGB(180, 198, 231)      
        Range(Cells(b, 31).Cells(b, 31)).Interior.Color = RGB(180, 198, 231)    
    End If
    
    
'   Region B
    If Cells(b, 1).Value = "Region B" Then
        Range(Cells(b, 1).Cells(b, 1)).Interior.Color = RGB(248, 203, 173)      
        Range(Cells(b, 7).Cells(b, 7)).Interior.Color = RGB(248, 203, 173)      
        Range(Cells(b, 24).Cells(b, 24)).Interior.Color = RGB(248, 203, 173)   
    End If

    If Cells(b, 1).Value = "Region B" And Cells(b, 25).Value = "Invalid" Then
        Range(Cells(b, 25).Cells(b, 29)).Interior.Color = RGB(248, 203, 173)   
    End If
        
    If Cells(b, 1).Value = "Region B" And Cells(b, 25).Value = "Invalid " Then   'space after invalid
        Range(Cells(b, 25).Cells(b, 29)).Interior.Color = RGB(248, 203, 173)   
    End If
                
    If Cells(b, 1).Value = "Region B" And Cells(b, 22).Value = 0 Then
        Range(Cells(b, 22).Cells(b, 22)).Interior.Color = RGB(248, 203, 173)    
    End If
    
    If Cells(b, 1).Value = "Region B" And Cells(b, 31).Value = "No info" Then
        Range(Cells(b, 31).Cells(b, 31)).Interior.Color = RGB(248, 203, 173)    
    End If

    b = b + 1

   Loop

  End sub

Again, I appreciate any help provided.
Thanks.

You need to give Excel a clue as to what sheet it is working on.
Take care to note where the extra point(full stops) and commas are (they are small but very important.
I have only correct the small piece of code, you will have to correct all the rest.

With ActiveSheet
    If .Cells(b, 1).Value = "Region A" Then
        .Cells(b, 1).Interior.Color = RGB(180, 198, 231)      'Region  This line is where Debug stops
        .Range(.Cells(b, 7), .Cells(b, 7)).Interior.Color = RGB(180, 198, 231)
        .Range(.Cells(b, 20), .Cells(b, 20)).Interior.Color = RGB(180, 198, 231)
        .Range(.Cells(b, 19), .Cells(b, 19)).Interior.Color = RGB(180, 198, 231)
    End If
End With

just re-read the code - most are single cells so address them as such - rows 4 & 5 can be amalgamated as a range.

.Range(.Cells(b, 19), .Cells(b, 20)).Interior.Color = RGB(180, 198, 231)

thanks for the feedback and added rep point - glad to have helped.